• Title/Summary/Keyword: The first return time

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QoS-based Optimal Timeslot Allocation for MF-TDMA Broadband Satellite Systems (MF-TDMA 광대역 위성시스템을 위한 QoS 기반 최적 타임슬롯 할당 체계)

  • Chang Kun-Nyeong;Lee Ki-Dong;Park You-Jin
    • Journal of the Korean Operations Research and Management Science Society
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    • v.29 no.4
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    • pp.141-157
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    • 2004
  • In this paper, we consider broadband satellite systems using MF-TDMA(Multi-Frequency Time Division Multiple Access) scheme. First, we analyze return link, superframe structure, and QoS( Quality of Service) parameters in broadband satellite systems, and mathematically formulate the QoS-based optimal timeslot allocation problem as a nonlinear integer programming problem for broadband satellite systems with clear-sky and rain-fade satellite terminals, and multiple data classes. Next, we modify the proposed problem to solve it within in a fast time, and suggest the QoS-based optimal timeslot allocation scheme. Extensive simulation results show that the proposed scheme finds an optimal solution or a near optimal solution within 5ms at Pentium IV PC.

The Symbolism of Color of Kas ya Interpreted by Paradign of Yin-Yang and Wu-Shing (음양오행의 틀로 해석한 가미색의 비교적 의미)

  • 은영자;김장향
    • Journal of the Korean Society of Costume
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    • v.40
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    • pp.25-35
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    • 1998
  • This thesis is a study of Kas ya, robes of buddhist monk, which is having peculiarity among human clothes. I kept my attention mainly on the symbolism of the color of Kas ya. To elucidate this, I chose the principle of T -chi and Yin-yang and Wu-shing as a frame-work of interpretation. In the first place, the original meaning of Kas ya mean a name of peculiar color. The concrete names of the color are color of persimmons juice, brown, yellow tinged with red, radish brown, non-primary color etc. The main motive to dye three robes of buddhist monk from white or primary color to the color of Kas ya was to differentiate buddhist monks from heathen or laymen. Therefore, as luxurious and primary colored cloths was donated to the buddhist monks, they are necessary to discolor them. Accordingly. they established 'non-primary color' as well-mate one for a ascetic. The non-primary color is called discolored color' as a result of discoloring primary colors. The discolored color is a synonym of Kas ya and the process of discoloring is necessary for making robes of buddhist monk. Secondly, discoloring means to mash five primary color. That is say, the process of discoloring means to return five primary colors back to 'profoundity·abstruseness·obscurity, namely darkness' as the source of them. Darkness as a condition amalgamated and not appeared all materials is the source and at the same time the terminus of all colors. Therefore, color of Kas ya symbolizes 'profound color' as the ultimate meaning of discoloring. Thirdly, discoloring garments of buddhist monk symbolize to destroy evil passions and haughtiness arising in ascetic's mind as well as means don't attach to the shaped materials'. Fourthly, discoloring means to return 'color'. namely 'all kinds of shaped material' to the inherent nature. Process of discoloring means to reture to the empty. nya. nya essentially do not make any colors, but over and over again come into being and become extinct as becoming colors. R pa, by one time Yin and the other time Yang'. R pa, color is a metaplasia of nya and nya is discoloring one of all colors. Then, discoloring means R pa is nya, R pa is nya at the same time and Because this is another expression of Dharma the original meaning of Kas ya symbolize true robes. Consequently, Kas ya means truth and beyond time and space do not be changed and conserve the color of the first till now.

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A Three-year Study on the Leaf and Soil Nitrogen Contents Influenced by Irrigation Frequency, Clipping Return or Removal and Nitrogen Rate in a Creeping Bentgrass Fairway (크리핑 벤트그라스 훼어웨이에서 관수회수.예지물과 질소시비수준이 엽조직 및 토양 질소함유량에 미치는 효과)

  • 김경남;로버트쉬어만
    • Asian Journal of Turfgrass Science
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    • v.11 no.2
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    • pp.105-115
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    • 1997
  • Responses of 'Penncross' creeping bentgrass turf to various fairway cultural practices are not well-established or supported by research results. This study was initiated to evaluate the effects of irrigation frequency, clipping return or removal, and nitrogen rate on leaf and soil nitrogen con-tent in the 'Penncross' creeping bentgrass (Agrostis palustris Huds.) turf. A 'Penncross' creeping bentgrass turf was established in 1988 on a Sharpsburg silty-clay loam (Typic Argiudoll). The experiment was conducted from 1989 to 1991 under nontraffic conditions. A split-split-plot experimental design was used. Daily or biweekly irrigation, clipping return or removal, and 5, 15, or 25 g N $m-^2$ $yr-^1$ were the main-, sub-, and sub-sub-plot treatments, respectively. Treatments were replicated 3 times in a randomized complete block design. The turf was mowed 4 times weekly at a l3 mm height of cut. Leaf tissue nitrogen content was analyzed twice in 1989 and three times in both 1990 and 1991. Leaf samples were collected from turfgrass plants in the treatment plots, dried immediately at 70˚C for 48 hours, and evaluated for total-N content, using the Kjeldahl method. Concurrently, six soil cores (18mm diam. by 200 mm depth) were collected, air dried, and analyzed for total-N content. Nitrogen analysis on the soil and leaf samples were made in the Soil and Plant Analyical Laboratory, at the University of Nebraska, Lincoln, USA. Data were analyzed as a split-split-plot with analysis of variance (ANOVA), using the General Linear Model procedures of the Statistical Analysis System. The nitrogen content of the leaf tissue is variable in creeping bentgrass fairway turf with clip-ping recycles, nitrogen application rate and time after establishment. Leaf tissue nitrogen content increased with clipping return and nitrogen rate. Plots treated with clipping return had 8% and 5% more nitrogen content in the leaf tissue in 1989 and 1990, respectively, as compared to plots treated with clipping removal. Plots applied with high-N level (25g N $m-^2$ $yr-^1$)had 10%, 17%, and 13% more nitrogen content in leaf tissue in 1989, 1990, and 1991, respectively, when compared with plots applied with low-N level (5g N $m-^2$ $yr-^1$). Overall observations during the study indicated that leaf tissue nitrogen content increased at any nitrogen rate with time after establishment. At the low-N level treatment (5g N $m-^2$ $yr-^1$ ), plots sampled in 1991 had 15% more leaf nitrogen content, as compared to plots sampled in 1989. Similar responses were also found from the high-N level treatment (25g N $m-^2$ $yr-^1$ ).Plots analyzed in 1991 were 18% higher than that of plots analyzed in 1989. No significant treatment effects were observed for soil nitrogen content over the first 3 years after establishment. Strategic management application is necessary for the golf course turf, depending on whether clippings return or not. Different approaches should be addressed to turf fertilization program from a standpoint of clipping recycles. It is recommended that regular analysis of the soil and leaf tissue of golf course turf must be made and fertilization program should be developed through the interpretation of its analytic data result. In golf courses where clippings are recycled, the fertilization program need to be adjusted, being 20% to 30% less nitrogen input over the clipping-removed areas. Key words: Agrostis palustris Huds., 'Penncross' creeping bentgrass fairway, Irrigation frequency, Clipping return, Nitrogen rate, Leaf nitrogen content, Soil nitrogen content.

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A Study of the Characteristics Times of Polymer Solutions Using the PIV System (PIV 시스템을 이용한 폴리머 용액의 특성시간에 관한 실험적 연구)

  • Lee, Jae-Su;Jeon, Chan-Yeal;Park, Jong-Ho
    • Proceedings of the KSME Conference
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    • 2004.11a
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    • pp.1552-1557
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    • 2004
  • Characteristics diffusion time of viscoelastic fluids are determined experimental results of terminal velocity by using the falling ball viscometer. The characteristics diffusion time of viscoelastic fluids are determined with help of the sphere device which is installed to return the dropped sphere from the bottom of the test cylinder without disturbing the working fluids. Terminal velocity of th sphere the reason why experimental of characteristics diffusion time that it is have an effect on the time interval of the measuring. Viscous of the fluid the temperature changed in order to have an effect on temperature and terminal velocity of the ball it becomes larger the possibility of knowing. A result of visualization for flow phenomena of around the sphere uses the PIV and the density of the polymer solution which it appears 2000wppm is to a case which is the right and left becomes symmetry to be it will be able to confirm and according to the time interval, to observed velocity vector of same at first drop the sphere.

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Design and Implementation of Dielectric Resonator Bandpass Filters with Various Time-Delay (다양한 시간지연을 갖는 유전체 공진기 대역통과 필터의 구현)

  • Choi, U-Sung;Park, Noh-Joon
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.14 no.11
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    • pp.2397-2402
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    • 2010
  • Dielectric resonator bandpass filters with various time-delay at 800MHz were designed and fabricated in this paper. from the results of this study. first of all, good response. characteristics were measured for all cases. The insertion loss was below 2dB and flatness for ripple was below 0.2dB, whereas return loss was over 20dB, respectively. The measured delay time of the fabricated prototype were 6ns, 12ns and 200s, respectively and the flatness characteristics did not exceeding Ins for all cases. Furthermore, 2~4ns of flatness were measured for 2-hole dielectric block and other dielectric resonator filters with various delay time by combination of each prototypes filters were also implemented.

Improving Compiler to Prevent Buffer Overflow Attack (버퍼오버플로우 공격 방지를 위한 컴파일러 기법)

  • Kim, Jong-Ewi;Lee, Seong-Uck;Hong, Man-Pyo
    • The KIPS Transactions:PartC
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    • v.9C no.4
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    • pp.453-458
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    • 2002
  • Recently, the number of hacking, that use buffer overflow vulnerabilities, are increasing. Although the buffer overflow Problem has been known for a long time, for the following reasons, it continuos to present a serious security threat. There are three defense method of buffer overflow attack. First, allow overwrite but do not allow unauthorized change of control flow. Second, do not allow overwriting at all. Third, allow change of control flow, but prevents execution of injected code. This paper is for allowing overwrites but do not allow unauthorized change of control flow which is the solution of extending compiler. The previous defense method has two defects. First, a program company with overhead because it do much thing before than applying for the method In execution of process. Second, each time function returns, it store return address in reserved memory created by compiler. This cause waste of memory too much. The new proposed method is to extend compiler, by processing after compiling and linking time. To complement these defects, we can reduce things to do in execution time. By processing additional steps after compile/linking time and before execution time. We can reduce overhead.

Analysis of Cluster-based Truck-Drone Delivery Routing Models (군집 기반 트럭-드론 배송경로 모형의 효과분석)

  • Chang, Yong Sik
    • Journal of Information Technology Applications and Management
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    • v.26 no.1
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    • pp.53-64
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    • 2019
  • The purpose of this study is to find out the fast delivery route that several drones return a truck again after departing from it for delivery locations at each cluster while the truck goes through the cluster composed of several delivery locations. The main issue is to reduce the total delivery time composed of the delivery time by relatively slow trucks via clusters and the sum of maximum delivery times by relatively fast drones in each cluster. To solve this problem, we use a three-step heuristic approach. First, we cluster the nearby delivery locations with minimal number of clusters satisfying a constraint of drone flight distance to set delivery paths for drones in each cluster. Second, we set an optimal delivery route for a truck through centers of the clusters using the TSP model. Finally, we find out the moved centers of clusters while maintaining the delivery paths for the truck and drones and satisfying the constraint of drone flight. distance in the two-dimensional region to reduce the total delivery time. In order to analyze the effect of this study model according to the change of the number of delivery locations, we developed a R-based simulation prototype and compared the relative efficiency, and performed paired t-test between TSP model and the cluster-based models. This study showed its excellence through this experimentation.

A Study on Oil Price Risk Affecting the Korean Stock Market (한국주식시장에 파급되는 국제유가의 위험에 관한 연구)

  • Seo, Ji-Yong
    • The Korean Journal of Financial Management
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    • v.24 no.4
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    • pp.75-106
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    • 2007
  • In this study, it is analyzed whether oil price plays a major role in the pricing return on Koran stock market and examined why the covariance risk between oil and return on stock is different in each industry. Firstly, this study explores whether the expected rate of return on stock is pricing due to global oil price factors as a function of risk premium by using a two-factor APT. Also, it is examined whether spill-over effects of oil price volatility affect the beta risk to oil price. Considering the asymmetry of oil price volatility, we use the GJR model. As a result, it shows that oil price is an independent pricing factor and oil price volatility transmits to stock return in only electricity and electrical equipment. Secondly, the two step-analyzing process is introduced to find why the covariance between oil price factor and stock return is different in each industry. The first step is to study whether beta risk exists in each industry by using two proxy variables like size and liquidity as control variables. The second step is to grasp the systematic relationship between the difference of liquidity and size and beta to oil price factor by using the panel-data model which can be analyzed efficiently using the cross-sectional data formed with time series. Through the analysis, we can argue that oil price factor is an independent pricing factor in only electricity and electrical equipment having the greatest market capitalization, and know that beta risk to oil price factor is a proxy of size in the other industries. According to the result of panel-data model, it is argued that the beta to oil price factor augments when market capitalization increases and this fact supports the first assertion. In conclusion, the expected rate of return of electricity and electrical equipment works as a function of risk premium to market portfolio and oil price, and the reason to make beta risk power differentiated in each industry attributes to the size.

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Consumers Preference and Dissatisfaction on knitted Golf Wear (골프니트웨어의 소비자 선호도와 불만족에 관한 연구)

  • 신상무;이종림
    • Journal of the Korean Society of Costume
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    • v.51 no.4
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    • pp.97-112
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    • 2001
  • The purposes of this study were to investigate consumers preference and dissatisfied factors in knitted golf wear The 430 questionnaires were sent to consumers who live in the Seoul Metropolitan district including Pundang-city and Iisan-city, The return rate was 89.5%. Statistical devices were t-test, ANOVA, $X$2. frequency with SAS program. The results of this study were as follows: First, Preferred colors were pastel, straw yellow, and black in descending order. Preferred coordination was analogous rather than complementary coordination. The classical look with T-neck, pullover, and V-neck was preferred. The preferred materials were pure cotton and cotton/wool blend in solid colors or plain and intasia structure. There were significant differences that pure cotton was preferred the forties and fifties or housewife, and cotton blend was preferred the thirties or service jobholders. Second, dissatisfied factors were pilling, deformation and de-coloration. The pilling problem was indicated in all income levels. Customers complained about no exchange and no refund policy with sales persons'discourtesy and time delay for repairing.

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Complete Transposition of the Great Arteries with Atrial Septal Defect -One Case Report- (대혈관 전위증 1예 보고)

  • 조건현
    • Journal of Chest Surgery
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    • v.12 no.3
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    • pp.197-206
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    • 1979
  • The most common abnormal relationship between the great arteries and ventricle is transposition of great arteries, among which complete D-transposition is a common and lethal malformation. Without appropriate treatment, the infant born with transposition of the great arteries rarely survives the first year of life. In contrast to the grim hopelessness of only a few years ago, modern aggressive palliative and corrective surgical interventions can provide such infants with considerable hope for adolescent and adult life. Up until this time, intraatrial baffle technique for re-direction of venous return, which was proposed by Mustard originally, has been successfully applied to infants and children in many foreign clinics with decreasing trend of the operative risk. In this report, we present one case of a 4 year-old girl having complete D-transposition of the great arteries with atrial septal defect, and reviewed the relevant literatures.

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